Method and apparatus for weighing waste signatures from a printing press

ABSTRACT

An automatic method and associated apparatus for weighing material and in particular for determining signature counts in association with a printing press. The system provides for the automatic registration of tare weight and for automatic removal detection and automatic registration of the last weight prior to removal. Also, in one embodiment described herein there is displayed a time signal representative of the time to go with regard to obtaining a desired full complement of good signatures.

BACKGROUND OF THE INVENTION

The present invention relates in general to a method and apparatus forweighing material and particularly an automatic counting and managementsystem used in conjunction with a printing press operation or otherconverting machinery operation. More particularly, the present inventionrelates to an automatic control and detection system that provides forsignature counting and also provides vital press information instantlyupdated and that continuously guides the press man in his operation.

It is an object of the present invention to provide an automaticcounting system for determining signature counts in association with aprinting press operation.

Another object of the present invention is to provide an automaticcounting system as in accordance with the preceding object and whichprovides for automatic detection of tare weight.

A further object of the present invention is to provide an automaticcounting system in accordance with the preceding objects and whichprovides for automatic waste bin or waste cart removal detection.

Still a further object of the present invention is to provide anautomatic counting system as in accordance with the preceding objectsand which provides for an automatic alarm, prior to desired removal of afull waste bin or waste cart.

Still another object of the present invention is to provide an automaticcounting system in accordance with the preceding objects and whichregisters the time remaining until the skid of wood sheets is consideredfull and ready for removal as a function of press speed.

SUMMARY OF THE INVENTION

To accomplish the foregoing and other objects of this invention inaccordance with one feature thereof, there is provided for the automaticdetection of tare weight by recording the first stable weight (stable,for example, for five seconds) once a predetermined minimum waste binweight has been exceeded. In accordance with this feature there isprovided an apparatus for weighing waste signatures in a waste bin takenfrom a printing press. This apparatus generally comprises a scale meansfor providing an electrical signal representative of cumulative weightof signatures along with the weight of the waste bin. Means are providedfor sensing movement of the waste bin on to the scale means to provide acontrol signal. In accordance with one aspect of the present inventionmeans are provided responsive to both the electrical signalrepresentative of scale weight and also the control signal for providingin an automatic manner a signal representative of the bin tare weight.The means for providing the signal representative of bin tare weightpreferably comprises sample and hold means having a sample input networkfor receiving the aforementioned control signal and having means forholding the electrical scale signal that is present at the time thecontrol signal is generated.

In accordance with another aspect of the present invention there isprovided the feature of automatically recording the last valid weight byfreezing the current value whenever there is erratic scale movement. Ifthe first stable (for, for example, five seconds) reading is below thepredetermined minimum waste bin weight, then the last frozen value wasthe full bin weight value. In accordance with this feature of theinvention, the apparatus may comprise means for sensing removal of thewaste bin from the scale means in an automatic fashion. This means forsensing removal of the waste bin may comprise separate means, one forsensing the full weight condition and a means for comparing the fullweight condition signal with the present electrical scale signal. Themeans for sensing full weight may comprise a sample and hold means andthe means for comparing may comprise a comparator and a divider networkfor providing an under 100% of full weight signal to the reference inputof the comparator.

Finally, in accordance with another aspect of the present inventionmeans are provided for generating a signal to be displayed that isindicative of the time remaining until a full compliment of goodsignatures has been obtained off of the press. In connection with thisfeature of the invention the apparatus comprises means for detectingtotal signatures from the press, means for weighing waste signatures,and means for deriving total good signatures by subtracting from thetotal signatures the waste signatures. Means are provided forestablishing a total desired count of good signatures and means areprovided for deriving a signal representative of the number ofsignatures-to-go to reach this desired total count. The press speed issensed such as by means of a rate meter and digital to analog converter.Finally, means are provided preferably in the form of a divider networkresponsive to press speed and the number of signatures remaining to go,to thus provide a signal representative of time to go to reach thedesired number of total good signatures.

BRIEF DESCRIPTION OF THE DRAWINGS

Numerous other objects, features and advantages of the invention shouldnow become apparent upon a reading of the following detailed descriptiontaken in conjunction with the accompanying drawing, in which:

FIG. 1 is a schematic diagram of a portion of one embodiment of a systemin accordance with the present invention; and

FIG. 2 is a schematic diagram showing the remainder of the system shownin FIG. 1; and

FIG. 3 is a time-weight graph useful in association with the diagrams ofFIGS. 1 and 2.

DETAILED DESCRIPTION

FIG. 1 is a schematic diagram illustrating a portion of the systemdescribed herein. The remaining portion of the system is shown in FIG.2. FIG. 3 is a graph of weight verses time that is helpful in explainingthe control provided by the concepts of this invention as embodied inFIGS. 1 and 2.

The graph of FIG. 3 may be broken down into different segments. SegmentA represents the time over which a storage bin or cart is placed uponthe scale. This segment is shown as perhaps being somewhat erratic whichoccurs when a cart is rolled on to a scale. For at least a short segmentB the weight is constant. This thus represents the tare weight asillustrated in FIG. 3. There is then a relatively long curve segment Cwhich is representative of a period over which the waste paper is beingdeposited in the storage bin on the scale. The next segment is segment Dwhich is shown as being cyclic representing erratic behavior that occursas the storage cart is about to be removed from the scale. This erraticbehavior is one of the parameters that is being sensed with thecircuitry of FIG. 1.

When the first set of wheels from the cart passes from the scale this isrepresented by the drop in the graph at segment E. There is also shown asegment F which represents the transition off of the scale when the lastwheel of the cart is removed from the scale.

FIG. 1 shows a preferred embodiment of the present invention. In theembodiment of FIG. 1 there is shown the scale 10 with the storage bin 12shown schematically above the scale 10. The scale 10 is of conventionaldesign and is considered in FIG. 1 as having an analog output on line 11that couples to an amplifier or driver 14 with the output thereofcoupling to the common line 16 where the signal SA (scale analog) isgenerated. The bin 12 is for containing waste paper coming from aprinting press or possibly from other like apparatus. The circuit ofFIG. 1 is adapted to provide certain control signals particularlyproviding an automatic signal representative of tare weight. This is thesignal TR shown in FIG. 1.

In FIG. 1, the description is in the form of analog circuitry. However,it is understood that it may be more advantageous to provide analogousdigital control, preferably by means of computer hardware/softwaretechniques.

In FIG. 1 the circuitry includes analog network 20 which has an outputcoupling to comparator 22. Another circuit that couples from the commonline 16 is the sample and hold circuit 24. The output of this circuitprovides the signal FW (full weight). Still another circuit that couplesfrom the common line 16 is the comparator 30. This circuit provides thesignal WB (waste bin on scale) and may also provide the negation of thatsignal. There is also shown a sample and hold circuit 36 and associatedlogic described in detail hereinafter. The sample and hold circuit 36 isfor generation of the tare weight signal TR.

Associated with the sample and hold circuit 36 there is detectioncircuitry including a monostable multivibrator or one-shot 50 andflip-flop 52. The one-shot 50 receives the signal ERR (erratic). This isthe signal taken from the output of the comparator 22.

Circuitry is also provided associated with the comparator 22 and thesample and hold network 24. This circuitry includes a multivibrator orone-shot 64 and flip-flops 66 and 68.

In FIG. 1 the comparator 22 is coupled to the common line 16 by way ofthe analog network 20. This network provides filtering by means ofcapacitor 21 and resistor 23 which essentially function as adifferentiator to detect any appreciable change in weight sensed at theline 16. The signal LIMIT at the reference input to the comparator 22 isset at a level corresponding to 0.30 pounds so that if there is a changeof weight of at least 0.30 pounds, then the comparator 22 is activatedindicating an erratic condition. This may occur when the cart is placedon the scale (segment A, FIG. 3) or is removed (segment D, FIG. 3) fromthe scale, or when an operator stands upon the scale to retrieve thewaste bin. However, the operator's weight is not included since it isnormally difficult for the operator to keep his movement to less than0.3 pounds. Thus, the signal FW is held to be the value just before theoperator stepped on the scale and the signal FW resumes when theoperator gets off the scale.

The signal ERR sets the flip-flop 66 and this signal also couples to theone-shot 64. Both the one-shot 64 and the one-shot 50 are retriggerableone-shots and the output shown in FIG. 1 from each of these has a fivesecond duration. The purpose of the one-shots is to have a five secondstable period. At the end of this period, at the falling edge 65 of thewaveform, the flip-flop 68 is triggered by this negative going edge. Thedata input to the flip-flop 68 is the signal WB. The output of theflip-flop 68 couples to the reset input of the flip-flop 66. Theassertion output of the flip-flop 66 in turn couples to the controlinput of the track and hold circuit 24.

The signal ERR taken from the output of the comparator 22, as indicatedpreviously, is generated whenever a change in weight is detected at thescale greater than the limit reference at the reference input to thecomparator 22. In one embodiment, this LIMIT reference is set at avoltage corresponding to 0.30 pounds of paper. Thus, each time thatthere is an output from the comparator 22, this signal sets theflip-flop 66. When the flip-flop 66 is set its output Q goes highcausing the circuit 24 to hold and cease continuous sampling. Prior tothe setting of flip-flop 66 the output Q is low controlling circuit 24to sample or track.

The signal ERR also couples to the one-shot 64 which is a retriggerableone-shot. Thus, as long as the signal ERR is generated, the one-shot 64is retriggered. However, at some point in time, after a predeterminedtime interval such as 5 seconds, after the one-shot 64 has timed outwithout being retriggered, there is a falling edge 65 that triggers theflip-flop 68. The flip-flop 68 senses the state of the signal WB. It isnoted that it is the affirmative of this signal that couples to the datainput of the flip-flop 68.

Thus, at the end of the one-shot time period, indicating a sufficientperiod of time over which erratic operation did not occur, then theflip-flop 68 determines whether the waste bin is on the scale or not. Ifthe waste bin is on the scale as represented by the signal WB, then theflip-flop 68 is set by the falling edge 65 and this signal couples backto the flip-flop 66 to reset the flip-flop 66.

The bin removal or erratic signals may be used as an indication to carryout other tasks in the weighing system such as use in conjunction withconveyor control.

With reference to FIGS. 1 and 3, it can be assumed that operationcommences by rolling the storage bin onto the scale 10. This is shown inFIG. 3 by the segment A. Note that during the segment A, the signal WBtransitions high. Now, it is noted that the segment B in FIG. 3 isrepresentative of a level that corresponds to the tare weight. The tareweight is detected by the sample and hold or tracking circuit 36 incombination with the one shot 50 and the flip-flop 52. Again, when thebin moves on to the scale, the signal ERR is generated and this iscoupled to the one shot 50. After the signal ERR is absent for at least5 seconds as determined by the one shot 50, then the output of the oneshot 50 has a negative transition 51 that couples to the clock input ofthe flip-flop 52. If the signal WB is low, the output of the flip-flopat its output Q is low and this enables tracking of the circuit 36.However, the erratic signal that occurs during segment A, once it hassettled down for 5 seconds, the signal WB is high because the waste binis then on the scale. Thus, when that setting of the flip-flop occurs,the Q output goes high and this holds the circuit 36 essentially holdingthe analog signal SA which becomes the tare weight signal representativeof the weight of the cart alone prior to any filling of the cart asoccurs along segment C in FIG. 3. Thus, the tare weight has beenmeasured automatically and there is no need to keep track of tare weightfor each different cart that may be employed. In the past separate tareweights were calculated for each cart and these tare weights were thenseparately used in making calculations. However, with the arrangement asillustrated in FIG. 1, now tare weight is detected automatically andthere is no need to keep track of tare weight for each cart that mightbe employed.

The operation continues through segment C with the waste bin beingfilled. Refer to the signal LIMIT and the comparator 22. When the signalto the comparator 22 exceeds the LIMIT the signal ERR (erratic) isgenerated.

When the flip-flop 66 was previously reset, this caused tracking by theanalog circuit 24. When the flip-flop 66 is set, this holds the finalvalue of the analog signal on line 16, indicated in FIG. 1 as the signalFW to indicate a cumulative weight condition.

Now, should an erratic signal be generated, say during segment C if theoperator should, for example, step onto the scale, this signal willcause a setting of the previously reset flip-flop 66. When this occurs,the output Q from the flip-flop 66 goes high and holds the analog signalat circuit 24. This has the effect of freezing the weight signal withtracking resuming only when the flip-flop 66 is reset. The erraticsignal will continue and even though the one-shot 64 provides for atiming out, as indicated previously, it is very difficult for theoperator to stand on the scale without causing some weight variationwhich will maintain the erratic signal. The erratic signal should onlycease after the operator gets off of the scale. Then, the one-shot 64times out and the trailing edge 65 clocks the flip-flop 68. Because thewaste bin is still on the scale, the output of the flip-flop 68 is highcausing a resetting of the flip-flop 66. This has the effect of resumingthe tracking because the output Q from the flip-flop 66 now goes lowwhich is indicative of its tracking mode. Furthermore, the tracking isresumed without having taken into effect that weight was added when theoperator got onto the scale. As far as a system is concerned, theoperator's weight is ignored.

FIG. 1 also shows the comparator 30 which receives the signal ESR shownas a threshold level H in FIG. 3. The signal ESR refers to an emptyscale reference. When the analog signal from line 16 exceeds thisreference, then the signal WB is generated, indicating that the wastebin is on the scale. It is noted that there is also provided in FIG. 1an inverter 31 for providing the negation of the signal WB, i.e. WB-.

There is also provided alarm means for signaling when the weight reachesa point close to where bin removal would be advisable. In this regardrefer to the alarm comparator 34 and the output signal AL. This is asignal that would be generated when the weight reaches a point close tothe end of the segment C in FIG. 3.

In FIG. 3 there is shown the segment D which is illustrative of a pointwherein the bin is removed from the scale again causing the erraticsignal to be generated, namely, the signal ERR. This erratic signal alsohas the effect of setting the flip-flop 66 to provide a holding of thesignal which in this case will be the true and final full weight signal.After the erratic signal ends and stability occurs for at least theaforementioned 5 seconds, then the signal at the output of the one-shot64 transitions at the falling edge 65 to clock the flip-flop 68.However, the signal WB is then low and thus the output from theflip-flop 68 does not reset the flip-flop 66. This thus means that thefull weight signal is temporarily held. The common occurrence of theclocking of the flip-flop 68 along with the WB signal being low is anindication that one is at a full weight condition and thus the signal atthe output of the circuit 24 can then be detected to determine what thisfull weight condition is.

In addition to the aforementioned alarm signal AL provided in FIG. 1 toindicate that the weight is approaching the maximum capacity of thestorage bin and scale, it is also advantageous to provide a signal to bedisplayed indicative of the time remaining before the printing run iscomplete. In this regard refer to FIG. 2 which shows a counter 40,digital to analog converter 42, analog networks 54 and 56, rate meter58, digital to analog converter 60, and divider network 44. The counter40 is shown as having a clock input at line 51. This is a pulse inputfrom the printing press indicating the gross output from the press. Theoutput of the counter 40 couples to the digital to analog converter 42and thus the output of the converter 42 is an analog signal at line 53representative of the present gross output of signatures from the press.This analog signal couples to the analog network 54 which is adifference or subtraction network. It is noted that this network alsoreceives the signal from the current 59. The signal on line 53 is onerepresentative of a gross (total) count of signatures from the presswhile the signal FW is representative of the full weight of waste. Thereis also provided in FIG. 2 a subtraction circuit 59 which provides forsubtraction of the tare weight. Thus, the waste count is actuallyrepresented by the full weight minus the tare weight and thus those twoinputs to the subtraction network 59 provide for a waste count. Thegross count minus the waste count is representative of good signatures.The network 54 being a difference network thus provides at its output 55an analog signal representative of the gross signatures minus wastesignatures which provides an indication of the good signatures that haveoccurred from the press. This signal couples to the second analognetwork 56 which also receives a signal on line 57 referred to as thesignal NGD (net good desired). This is a reference signal that may beset in a predetermined manner and is a signal of a magnituderepresentative of the net good signatures that are desired. The network56 is also a difference or subtraction network and thus the output atline 49 is the signal NTG (needed-to-go) which is a signal indicative ofthe number of good signatures that are still required before the totalnumber of good signatures is reached.

The pulse input signal on line 51 couples to a rate meter 58 which maybe of conventional design providing a digital output that couples to thedigital to analog converter 60. This arrangement provides for an analogsignal at the output line 62 from the converter which is a signalrepresentative of press speed. The signal on line 62 couples to thedivider network 44. Also the divider network 44 receives the signal online 49 mentioned previously. The output of the divider network is thesignal TTG (time-to-go).

The time-to-go until the job is finished is represented by the ratio ofthe number of signatures that are still needed divided by the pressspeed. This division is carried out by the divider 64 which receives thesignal representative of the press speed on line 62 and the secondsignal on line 59 which is representative of the number of signaturesthat are required to go. Thus, as indicated on the output line 63 fromthe divider 44 there is the signal TTG which is representative of thetime-to-go until the desired number of total good signatures isobtained.

Having now described one embodiment of the present invention, it shouldnow be apparent to those skilled in the art that numerous otherembodiments are contemplated as falling within the scope of thisinvention.

What is claimed is:
 1. Apparatus for weighing waste signatures in awaste bin and taken from a printing press or the like comprising:scalemeans for providing an electrical signal representative of cumulativeweight of waste signatures in the waste bin, means for sensing movementof said waste bin onto the scale means to provide a control signal, andmeans responsive to both said scale means signal and the control signalfor automatically providing a signal of bin tare weight, said means forsensing including differentiator means for detecting any appreciablechange in sensed weight occasioned by movement of the waste bin onto thescale means, said control signal including a first signal that isindicative of erratic weight behavior as occurs when the waste bin ismoved onto the scale means followed by a second signal generated by saidmeans for automatically providing for holding the electrical scalesignal that is present at the time the second signal is generated. 2.Apparatus for weighing waste signatures as described in claim 1 whereinsaid means for providing a signal of bin tare weight comprises a sampleand hold means having a sample input coupled from said scale means and acontrol input, and delay means for providing said second signal thatcouples to the control input of the sample and hold means.
 3. Apparatusfor weighing waste signatures as described in claim 1 wherein said meansfor providing a signal of bin tare weight comprises sample and holdmeans having a sample input network.
 4. Apparatus for weighing wastesignatures as described in claim 3 wherein said sample input networkcomprises a bistable means for receiving a control signal indicative ofthe waste bin being on the scale and gate means.
 5. Apparatus forweighing waste signatures as described in claim 4 wherein said means forsensing movement comprises means for comparing the electrical scalesignal and a reference signal representative of an empty scale. 6.Apparatus for weighing waste signatures as described in claim 1including comparator means having one input coupled from the scale meansto monitor the electrical signal therefrom and a second input forreceiving an alarm reference signal.
 7. Apparatus for weighing wastesignatures as described in claim 1 including sample and hold means forregistering a full weight condition.
 8. Apparatus for weighing wastesignatures in a waste bin and taken from a printing press or the likecomprising;scale means for providing an electrical signal representativeof cumulative weight of waste signatures and the waste bin, means forsensing movement of the waste bin onto the scale means includingdifferentiator means for detecting any appreciable change in sensedweight occasioned by movement of the waste bin onto or off of the scalemeans to thereby establish a first control signal that is indicative oferratic weight behavior as occurs when the waste bin is moved onto oroff of the scale means, means for sensing removal of the waste bin fromthe scale means, means for establishing a second control signal upontermination of the first control signal indicative of cessation of theerratic weight behavior, and means responsive to both said secondcontrol signal and the removal of the waste bin for providing a fullweight signal.
 9. Apparatus for weighing waste signatures in a waste binas described in claim 8 wherein said means for establishing a secondcontrol signal including delay means for establishing a delay periodfollowing the erratic weight period.
 10. Apparatus for weighing wastesignatures in a waste bin as described in claim 9 wherein said means forproviding a full weight comprises sample and hold means.
 11. Apparatusfor weighing waste signatures in a waste bin as described in claim 10wherein said sample and hold means as a sample input coupled from saidscale means and a control input controlled from said second signal. 12.Apparatus for weighing waste signatures in a waste bin taken from aprinting press or the like comprising;means for detecting totalsignatures from the press, means for weighing waste signatures, meansfor deriving total good signatures by subtracting from said totalsignatures the waste signatures, means for establishing a total desiredcount of good signatures, means for deriving a signal representative ofthe number of signatures to go to reach the desired total count, meansfor sensing press speed, and means responsive to press speed and numberof signatures to go to provide a signal representative of time to go toreach the desired number of total good signatures.
 13. Apparatus forweighing waste signatures in a waste bin as described in claim 12wherein said means for detecting total signatures includes counter meansand converter means.
 14. Apparatus for weighing waste signatures in awaste bin as described in claim 13 wherein said means for deriving totalgood signatures comprises difference circuit means.
 15. Apparatus forweighing waste signatures in a waste bin as described in claim 14wherein said means deriving signatures to go comprises second differencecircuit means.
 16. Apparatus for weighing waste signatures in a wastebin as described in claim 15 wherein said means to provide a signal oftime to go comprises divider means.
 17. Apparatus for weighing wastesignatures in a waste bin as described in claim 12 wherein said means toprovide a signal of time to go comprises divider means.